1 字符串拼接

l=[1,2,3,4,5,6,7,8,9]
str1=''
for i in range (0,9):
    a=str(l[i])
    str1=str1+a
print(str1)

2 循环

L=[1,2,3,4,5,6,7,8,9]
a=1
for i in range(1,9):
    a=a*10+L[i]
print(a)

3 python內建的高阶函数 join

list=[1,2,3,4,5,6,7,8,9]
l=[]
for i in range (0,9):
    l.append(str(list[i]))
print(''.join(l))